Hello @matsujirushi , Thanks for reaching out to us on this document.
It appears the documentation needs to be updated, I have reached out to the engineering team and will have an update soon next week.
Please stay tuned to this post for further updates.
Update:11/24/2020
Below is the mapping of the enum to the exact UpdatePolicy string:
0 = UpdateAll
1 = No3rdPartyAppUpdates
2 = NoUpdates
Please note that there are only 3 enum values as of now, we will soon update the REST API document.
Thanks,
Satish.